1. Field of the invention
The present invention relates to a lens-integrated optical waveguide and a method of making a lens-integrated optical waveguide.
2. Description of Related Art
Referring to FIG. 1, lights transferring is shown between a transferring waveguide and a receiving waveguide, each having a planar base 22, a plurality of optical cores 20, and a cladding 24 covering the base 22 and the core 20. There is no lens between the two waveguides. Therefore, some of the lights from the transferring waveguide are scattered and not received by the optical core 20 of the receiving waveguide.
U.S. Pat. No. 6,625,351, issued to Cox et al. on Sep. 23, 2003, discloses that collimating microlenses are “printed” from optical polymeric materials on ends of optical fibers using ink-jet technology. In one embodiment the optical fibers are inserted into a collet, a stand-off distance from the open upper end of the collet. The open upper end is filled with optical fluid and a microlens is formed thereon to collimate light exiting the fiber through the microlens. In another embodiment optical fibers from a “ribbon” are separated and installed into a ferrule having multiple openings therethrough. In the same manner as in the collet embodiment, the ferrule openings serve as a mold for the lens formation with the end of the fiber being located at the focal distance of the lenslet formed in an on the ferrule. A non-wetting coating can serve to control spreading of the fluid optical material and allow lens radius control as well. The microlenses are hardened after formation.
U.S. Pat. No. 7,137,746 issued to Cato on Nov. 21, 2006, discloses a method to integrally form a lens on an end of an optical waveguide structure. The lens is formed on a cross-section of optical fiber which has been cut perpendicularly to a waveguide path corresponding to a light-receiving element and polished to make it flat. A specific method of forming the lens is to blow about one drop per one optical fiber of a liquid ultraviolet hardening resin by ink jet technology or the like, and then expose it to ultraviolet light to harden the resin. The shape of the lens does not need to be controlled precisely partly because the lens diameter is smaller, and lens formation can be achieved with good reproducibility by adjusting the viscosity of the ultraviolet hardening resin or other resin.
There is a need to provide a different lens-integrated waveguide.